Add `ard_*()` function for `stats::poisson.test()` #304

All 105 tests pass in 1m 0s

1 files ±0 105 suites +1 1m 0s ⏱️ -2s
105 tests +1 105 ✅ +1 0 💤 ±0 0 ❌ ±0
582 runs +1 582 ✅ +1 0 💤 ±0 0 ❌ ±0

Results for commit d38cc2e. ± Comparison against earlier commit 257c585.